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HBASE-4408. book.xml, faq 

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1170819 13f79535-47bb-0310-9956-ffa450edef68
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Doug Meil 2011-09-14 19:55:57 +00:00
parent 0b83bf1d7a
commit b048ee1466
1 changed files with 29 additions and 12 deletions
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src/docbkx/book.xml
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@ -1702,6 +1702,23 @@ hbase> describe 't1'</programlisting>
<title >FAQ</title>
<qandaset defaultlabel='faq'>
<qandadiv><title>General</title>
<qandaentry>
<question><para>When should I use HBase?</para></question>
<answer>
<para>
Anybody can download and give HBase a spin, even on a laptop. The scope of this answer is when
would it be best to use HBase in a <emphasis>real</emphasis> deployment.
</para>
<para>First, make sure you have enough hardware. Even HDFS doesn't do well with anything less than
5 DataNodes (due to things such as HDFS block replication which has a default of 3), plus a NameNode.
Second, make sure you have enough data. HBase isn't suitable for every problem. If you have
hundreds of millions or billions of rows, then HBase is a good candidate. If you only have a few
thousand/million rows, then using a traditional RDBMS might be a better choice due to the
fact that all of your data might wind up on a single node (or two) and the rest of the cluster may
be sitting idle.
</para>
</answer>
</qandaentry>
<qandaentry>
<question><para>Are there other HBase FAQs?</para></question>
<answer>
@ -1738,18 +1755,6 @@ hbase> describe 't1'</programlisting>
</para>
</answer>
</qandaentry>
<qandaentry xml:id="brand.new.compressor">
<question><para>Why are logs flooded with '2011-01-10 12:40:48,407 INFO org.apache.hadoop.io.compress.CodecPool: Got
brand-new compressor' messages?</para></question>
<answer>
<para>
Because we are not using the native versions of compression
libraries. See <link xlink:href="https://issues.apache.org/jira/browse/HBASE-1900">HBASE-1900 Put back native support when hadoop 0.21 is released</link>.
Copy the native libs from hadoop under hbase lib dir or
symlink them into place and the message should go away.
</para>
</answer>
</qandaentry>
</qandadiv>
<qandadiv xml:id="ec2"><title>EC2</title>
<qandaentry>
@ -1796,6 +1801,18 @@ When I build, why do I always get <code>Unable to find resource 'VM_global_libra
</para>
</answer>
</qandaentry>
<qandaentry xml:id="brand.new.compressor">
<question><para>Why are logs flooded with '2011-01-10 12:40:48,407 INFO org.apache.hadoop.io.compress.CodecPool: Got
brand-new compressor' messages?</para></question>
<answer>
<para>
Because we are not using the native versions of compression
libraries. See <link xlink:href="https://issues.apache.org/jira/browse/HBASE-1900">HBASE-1900 Put back native support when hadoop 0.21 is released</link>.
Copy the native libs from hadoop under hbase lib dir or
symlink them into place and the message should go away.
</para>
</answer>
</qandaentry>
</qandadiv>
<qandadiv><title>How do I...?</title>
<qandaentry xml:id="secondary.indices">